topic About HDMI TMDS Guard bands setting(IM8MP). in i.MX Processors

About HDMI TMDS Guard bands setting(IM8MP).

Yoshiharaaa — Wed, 15 Nov 2023 07:40:48 GMT

Hi,everyone

I am using I.MX8MP.
During HDMI output I get an error that the guard band for the data island does not exist.
Before Data Island, fixed data "1" is used as Leading Data Island.
After Data Islanding, fixed data Ch1 and Ch2 should be set to "0100110011" as Trailing Data Island.
Is there any way to enable or disable this setting?
Can it be controlled again?

I would like to know how to solve this problem.

Best regards.
/yoshihara

Re: About HDMI TMDS Guard bands setting(IM8MP).

Yoshiharaaa — Wed, 22 Nov 2023 06:15:47 GMT

11/22/'23 Added

While running HDMI compliance tests, I discovered that the real reason Guardband wasn't outputting was that it couldn't switch between HDMI and DVI.
Therefore, the Guardband output appears to be working properly.

I'm trying to modify the registry to switch the output mode after reading the EDID, but it's not working.
We are currently investigating this issue.

If you have an answer to this problem, please let us know.

Re: About HDMI TMDS Guard bands setting(IM8MP).

brian14 — Wed, 22 Nov 2023 18:56:02 GMT

Hi @Yoshiharaaa,

Thank you for contacting NXP Support.

I'm reviewing your case. Could you please explain me more about the modifications that you are trying to do for switching the output mode?

Re: About HDMI TMDS Guard bands setting(IM8MP).

Yoshiharaaa — Mon, 04 Dec 2023 08:36:50 GMT

@brian14 -san

Sorry for the late reply.
I researched this issue and was able to resolve it the other day.
The reason for not being able to switch HDMI/DVI after obtaining EDID was in the user application.
It seems that it was not processed correctly after reading EDID.

HDMI compliance test passed successfully.
Thank you for your support.

thank you,

Yoshihara